Hit enter too soon, sorry. Omit the last paragraph and continue here:
In fact, for Mars missions, it’s often better to break up the launch into several steps anyway. The reference mission calls for landing an empty return vehicle on Mars before the crew ever takes off, which also allows it time to establish a base and process local resources. The crew would leave Earth knowing that a fully-fueled return vehicle is already waiting for them, and that it has already gone through and survived the most dangerous part of the trip: landing.
“Orbital construction” and “fuel transfer” sound cool, but we don’t need them for Mars or the asteroid belt. Maybe we’ll need them for Jupiter missions, or maybe we will have built enough stuff on Mars in the meantime that we can launch directly from there or the asteroid belt.
Engineers call stuff like orbital construction “a solution looking for a problem.”
